In U. S. History, 19th Century use of the term "American Frontier" refers to A)
the area where pioneer settlement ended.
 
B)
the Atlantic or Pacific coast of North America.
 
C)
the territory east of the Appalachian Mountains.
 
D)
any territory beyond the thirteen original colonies.
 

A

Explanation:frontiers are borders and borders are where settlers arnt

well the fact it is basically a peninsula allowed trade to come from many places, thus allowing cultural diffusion to take place. india has seasonal monsoons that merchants travel back and forth from india using the monsoons wind patterns